Mahdi Khanfar, a 35-year-old graduate in urban development, still trembles at the memory of his arrest by the Palestinian Authority's mukhabarat (intelligence service) in May. "The mukhabarat asked me about Hamas and weapons. They put me in a zinzana [a small windowless cell] at mukhabarat headquarters in Jenin and started hanging me with my hands tied behind my back.
"My toes were only just touching the floor. Sometimes they also tied one leg so I had only one foot on the ground. It lasted for five days. I've lost all feeling in my left hand," he told the Guardian last week.
One of several former detainees interviewed in Nablus and Jenin, he described what appeared to be a pattern in which Hamas sympathisers are often only released on production by their families of money or guns. The alleged abuse by PA forces appears to be aimed at convincing western donor governments, as well as Israel, that the authority is "clamping down on terror".
Khanfar's brother works in Qatar as news director of the Arab satellite TV station al-Jazeera. "They kept asking me about al-Jazeera broadcasts, which they didn't like. I said that's my brother's business. This is crazy. They contacted Hikmat, my other brother, in Jenin and told him that if he wanted to have me free he should bring a weapon. Hikmat contacted the International Committee of the Red Cross who sent a delegate to see me. My treatment improved slightly but I was held for several more days, until after 53 days I was released."
Fadel Morshed, 40, is a lawyer who has defended Hamas detainees. Arrested by the Jenin mukhabarat in January, he says he was kept for the first three days hanging with his hands behind his back. The torture, which creates massive pain without breaking any bones, is known as shabah. In a variant, Morshed was later tied to a stool fixed to the floor beneath the stairs so he had to crouch for hours at a time.
"They asked me why I defended Hamas people. I refused to answer and said that as a lawyer I was not required to discuss my clients with them," Morshed told the Guardian. "All the people arrested are moderates who favour unity and dialogue with Fatah. They were not part of Hamas's military wing." He was released after 45 days without explanation or charge but still has sores and swellings on his feet.
Some victims have been arrested more than once. Sheikh Hamid Betawi is head of the Sharia Court of Palestine and a member of the Palestinian parliament, elected on the Hamas-supported list, Reform and Change. He described how his 30-year-old son, Naser, a shopkeeper and father of two, was held and tortured by the mukhabarat in Nablus from March to May this year.
For the first month the family were barred from visiting. "When his wife was let in, the mukhabarat told her to provide money or weapons. Almost every prisoner is told to get money or weapons. Many do. There are plenty of gun-traders," the sheikh said. She sold gold jewellery to raise the money to get him out, but a few weeks later he was arrested again.
"We're facing two occupations, an Israeli one and a Palestinian one," said Sheikh Betawi. "I spoke to Abu Mazen [Mahmoud Abbas] the other day about the attacks on Hamas but nothing has changed," he added. The sheikh is convinced that European donor governments as well as Lieutenant-General Keith Dayton, the US officer overseeing security sector reform for the Palestinian Authority, is aware of what's happening.
Jamal al Muhaisen, the governor of Nablus, an appointee of Abbas's Fatah party, admitted that detainees are routinely swapped for guns. "We only arrest people who may have weapons. If a person delivers a weapon, of course the next day we will release him," he said. He denied torture was a matter of policy. "We refuse to adopt harsh measures but sometimes people who work in prison commit mistakes and we're not happy. It happens in every country, including the United States."
Nablus has also seen almost nightly incursions by Israeli troops over the past few weeks, who have raided six mosques, closed three schools, a clinic, a TV station, a women's group and the charity, Attadamun, which helps orphaned children. The Israeli foreign ministry describes the army's actions, which have also hit hard in Hebron in recent months, as targeted at Hamas's "organisational infrastructure".
"The Hamas activity is carried out under the guise of charity, but the actual aim is the strengthening of the Hamas terror organisation and its grip on the population," a ministry statement said. Hamas wanted to gather strength in the West Bank so as to get control just as it did last year in Gaza, it added.
Up to 200 people have been arrested by the Israelis, according to Governor Muhaisen. But although Nablus's governor criticises the Israeli incursions, many in Nablus see Fatah's relationship with the Israelis as one of collusion more than competition. They point to a revolving door of back-to-back arrests, in which people detained by the Israelis are later held by the Palestinians, or vice versa.
Dr Mustafa Barghouti, the secretary-general of the Palestinian National Initiative and an independent MP who criticises both Fatah and Hamas, said: "Since Annapolis there have been 2,560 Israeli attacks on Palestinians, 90% of them in the West Bank. They've undermined the PA by their actions. They're trying to turn the PA into a security sub-agent like the Vichy government (in occupied France)."